1. Field of the Invention
The present invention relates to a stacked semiconductor package, and more particularly to a stacked semiconductor package having wires with different diameters.
2. Description of the Related Art
FIG. 1 shows a top view of a conventional stacked semiconductor package without a molding compound. FIG. 2 shows a cross-sectional view of the conventional stacked semiconductor package. The conventional stacked semiconductor package 1 comprises a substrate 11, a first die 12, a second die 13, a plurality of first wires 14, a plurality of second wires 15 and a molding compound 16.
The upper surface of the substrate 11 has a plurality of fingers 111, a ground ring 112 and a power ring 113. The fingers 111, the ground ring 112 and the power ring 113 surround the first die 12 and the second die 13. The lower surface of the first die 12 is adhered to the upper surface of the substrate 11 by an adhesive 17. The upper surface of the first die 12 has a plurality of first pads 121. The first wires 14 electrically connect the first pads 121 to the ground ring 112 or the power ring 113.
The lower surface of the second die 13 is adhered to the upper surface of the first die 12 by an adhesive 18. The upper surface of the second die 13 has a plurality of second pads 131. The second wires 15 electrically connect the second pads 131 to the fingers 111, the ground ring 112 or the power ring 113. The molding compound 16 encapsulates the upper surface of the substrate 11, the first die 12, the second die 13, the first wires 14 and the second wires 15.
The conventional stacked semiconductor package 1 has the following disadvantages. The diameters of the first wires 14 and the second wires 15 are the same, causing a waste of material. In particular, the material of the conventional wires is almost always gold, and this increases the manufacturing cost. Moreover, the first wires 14 cannot be arranged with an arc that has a small radius, or the neck would be easily torn apart, but if the radius of the arc of the first wires 14 is too large, the first wires 14 would have a risk of touching the second wires 15.
Therefore, it is necessary to provide an innovative and advanced stacked semiconductor package to solve the above problems.